A computer aided design (CAD) technology has been utilized in various types of design processes. An example of the CAD includes an electric CAD that may include a printed circuit board (PCB) CAD (mounting CAD) configured to place components of the PCB and route wires between the components. Designers of the PCB, for example, may place the components of the PCB and route the wires of the PCB by utilizing the PCB CAD.
In the PCB, a field-programmable gate array (FPGA) that is a component including swappable pins may be utilized. Examples of swapping of the pins are illustrated in FIGS. 1 and 2.
FIG. 1 is a conceptual diagram illustrating an example of a tangled rat's nest. The rat's nest indicates connecting lines between nodes. The rat's nest represents a logical connection relationship between the nodes. FIG. 1 illustrates the tangled rat's nest representing the connections between the pins of a component 1 and the pins of another component (not illustrated). For example, some of the pins may be swapped with corresponding pins to minimize tangles of the rat's nest in FIG. 1. FIG. 2 is a conceptual diagram illustrating an example of a rat's nest in which the tangles are minimized after some of the pins are swapped with the corresponding pins.
For example, since the FPGA that is an example of the component including swappable pins includes the increased number of pins and plural I/O banks, the high-speed and high-density FPGA may be achieved. Accordingly, it may be difficult to manually allocate I/O pins to minimize the tangles of the rat's nest.
In an example of the related art routing processing apparatus, if crossing (i.e., tangle) of a net is avoidable by replacing a specific node with a node equivalent to the specific node (hereinafter called an equivalent node), the specific node is replaced with the equivalent node in advance and then conductor patterns are routed on the PCB. Another example of the related art discloses a routing processing system that may improve operability of the routing processing system by reducing manual operations involving replacement of a certain node with an equivalent node or routing of conductor patterns (e.g., Japanese Laid-Open Patent Application Publication No. 9-44538).